Field expedient radioactive waste incinerator



July 1, 1969 J, L T O ET AL 3,452,690

FIELD EXPEDIENT RADIOACTIVE WASTE INCINERATOR Filed Dec. 8, 1967 Sheetof2 INVENTORS James L. Tarbox David G. LachapeI/e wwilwfm gm 1ATT'ORNEYS Jul 1, 1969 J. L. TARBOX E 3,452,690

FIELD EXPEDIENT RADIOACTIVE WASTE INCINERATOR Filed Dec. 8, 1967 Sheet 2of 2 INVENTORS James L. Tarbox David 6. Lac/mpe/le United States Patent3,452,690 FIELD EXPEDIENT RADIOACTIVE WASTE INCINERATOR James L. Tarbox,Towson, and David G. Lachapelle, Joppa, Md., assignors to the UnitedStates of America as represented by the Secretary of the Army Filed Dec.8, 1967, Ser. No. 689,194 Int. Cl. G21f 9/14, 9/32; F23g 9/00 U.S. Cl.110-7 7 Claims ABSTRACT OF THE DISCLOSURE The invention described hereinmay be manufactured, used, and licensed by or for the Government forgovernmental purposes without the payment to us of any royalty thereon.

Our invention relates to a portable incinerator for disposal ofcombustible radioactive waste.

The advent of nuclear activities has necessitated incineration as ameans of disposing of combustible radioactive waste. To appreciate theneed for a portable incinerator, one need only consider the event of alarge scale radioactive contamination resulting from an accidentalrelease of radioactivity as through a weapons accident or from enemyaction which would result in many radioactive contaminated combustiblestructures, such as buildings and materials, which could be effectivelydisposed of, to re- A principal object of our invention is to design,construct, and operate a portable combustible radioactive wasteincinerator which can be quickly assembled and placed in efiicientoperation and produce minimum pollution to the environment resulting ina minimum health hazard.

A further object of our invention is to design, construct, and operatean etficient portable combustible radioactive waste incinerator which iseconomical.

Other objects of our invention will be obvious or will appear from thespecification hereinafter set forth.

After our portable incinerator was designed and constructed, it wastested for efficiency of operation and minimal radioactive contaminationto the atmosphere by four separate burns in which the incinerator chargewas oak lumber coated with radioactive material as follows:

Burn I Approximately 0.169 curie of lanthanum-140* tagged particlesranging from 75-150 microns were aflixed to the lumber.

Hum 11 Approximately 0.213 curie of lanthanum-140 in solution wasbrushed onto the lumber.

Burn III Approximately 2.082 curie of lanthanum-140 tagged particlesranging from 20-75 microns were dusted over the lumber.

Burn IV TABLE.-RESUME OF INCINERAIION TESTS Time Amount of ActivityWeight (1b.) Activity (curie) Burn Date, contamination applied, No. 1966Start End Contamination type applied curie Lumber Ash Ash Efiiuent I 22Oct 0923 1245 S0lida75-150 simulant hand spreader 12 1b O. 169 2, 00022. 5 0. 1227 0. 00002 use II 31 Oct 0943 1333 Liquid, LaCl; in acidsolution. 4 gal 0.213 2, 000 17. 5 0.00307 III- 4 Nov 1445 1740 Solid,20-75; simulant vortex dispenser 1 lb 2. 082 2, 000 17. 0 0. 00302 useIV 10 Nov 1100 1430 Liquid, LaOl in acid solution. 4 gal 1.833 2, 00012. 5 0. 02730 move the radioactivity hazard, through means of portableFIGURE 1 is a view of the assembled portable inincinerators erected atthe contaminated site in a few man-hours.

Paramount in the incineration of contaminated combustible materials isthe confinement of as much of the radioactivity in the incinerator as ispossible. It is essential that the environment be polluted to anabsolute minimum during the burning operation. Also, in an emergencysituation, it must be possible to set the incinerator up quickly,efliciently, and economically. Considerable development work had beendone on incinerators capable of burning radioactive Wastes prior to ourinvention. However, all of these incinerators, such as described andshown in U.S. patent application of James L. Tarbox, Ser. No. 652,636filed on July 11, 1967, were large, complicated, fixed installation typeincinerators which were not adaptable for portable use.

The above discussed problem led to the concept and reduction to practiceof our efficient, economical, quickly assembled, and portableincinerator.

cinerator.

FIGURE 2 is a view of the spark arrester and top of the incinerator withthe instrumentation mounting structure removed.

FIGURE 3 is a top view of the incinerator shown in FIGURE 1.

Our invention and FIGURES 1 to 3 will now be described in detail asfollows:

FIGURE 1 shows our portable combustible radioactive waste incineratorcomprising three tiers or sections, 1, 2, and 3, nesting within and heldwithin each other by the tiers own weight. Each tier comprises 12panels, character 12 in the drawing, fabricated from standard four byeight foot steel plate, inch thick; the panels being bolted together andhaving the geometrical configuration of a twelve sided truncated cone.When assembled, the three tiers have a base diameter of about ten feet,a top diameter of about three feet, and a total height of about thirteenfeet. Mounted on top of the three tiers is a three foot highcylindrically shaped screen structure of 12 gauge locomotive netting, 11gauge woven wire 4 x 4 openings per inch, 11, which serves as a sparkarrester, during the burning operation. Three oil-fired burners, 4, arelocated in the primary tier, 3, at a height of two feet above the groundon 120 centers and fired toward the center of-the pit, 8, at an angle ofabout 30 downward, relative to the horizontal plane. Two oil-firedburners, 5, are mounted in secondary tier, 2, at a height of five andtwo-thirds feet above the ground, on 180 centers, and offset from eachother as shown in FIGURE 3. The purpose of the offset arrangement beingto induce tangential flow and produce more eflicient combustion of thegases. Dampers, 6, are provided in all panels of the lower two sectionsto provide both excess air for combustion and cooling air for the wallsof the incinerator. Structure is merely a mounting structure forinstrumentation used in testing the 'efficiency of operation, andstructure 10 is not necessary to the operation of our incinerator asshown in FIGURE 2, but could be utilized to test efliciency of operationwhen desired. Door, 7, is provided to place the combustible radioactivewaste charge within the incinerator to be burned. When assembled, thethree tiers are located over a four foot deep ash pit, 8, lined with asteel basin, 14; the pit having a top diameter of about nine feet and abase diameter of about 6 feet. The pit is merely a hole dug in theground at the contaminated site. As can readily be seen, when theburning operation is completed the incinerator can be collapsed into thepit, and the pit closed with earth due to economical cost of theincinerator component parts and materials. The pit is provided with agrate, 9, fabricated from railroad rail and a six inch diameter pipe,13, for externally supplied forced air draft. The oil-fired burners 4and 5 are conventional commercially available units such as utilized inhome heating systems. Each of the burners has a continuous ignition, notshown in the drawing, and an oil recycle system, not shown in thedrawing. A common motor, not shown in the drawing, on each burner drivesboth the air blower section, not shown in the drawing, and the oil pump,not showing in the drawing, and the ignition system is electricallyindependent of the blower-pump section. With the ignition off and theblower-pump section operating, fuel is recycled from a fuel storagetank, not shown in the drawing, through the oil pump and dischargesthrough a solenoid valve, not shown in the drawing, back to the fuelstorage tank. This recycle system was necessary due to the type of oilpump utilized, a pump which utilized the fuel as a pump lubricant. Also,with the ignition off, the burner units can be used as a source ofoverfire combustion air. In operation, primary burners, 4, are used inthe firing mode until the charge of combustible radioactive waste beginsto burn freely by itself. When free burning of the charge begins, theprimary ignitions are switched off and primary burners, 4, utilized foroverfire air supply only. The two secondary burners, 5, are firedcontinuously for the duration of the burning operation and serve asafter burners to minimize discharge of any unburned radioactive materialthat might rise from the primary combustion section 3. As mentionedabove, combustion air and surface cooling was provided by damper means,6. Underfire air was supplied through six inch ducting, 13, connected toa centrifugal blower, not shown in the drawing, having a capacity of 570c.f.m.

It is obvious that other modifications can be made of our invention, andwe desire to be limited only by the scope of the appended claims.

We claim:

1. A portable combustible radioactive waste incinerator comprising afirst lower section; a second center section; a third upper section;each section comprising a number of panels assembled together; saidsections being nested together; a spark arrester nested within saidthird section; a door within said first section to place a radioactivecharge within the incinerator; burner means mounted within said firstsection to ignite said charge; damper means within said first and secondsection to provide combustion air and surface cooling air; burner meanswithin said second section to function as after burners; said first,second, and third sections being mounted over a pit means; grate meanswithin said pit means; forced draft means to supply air to said pitmeans; means to supply fuel to said burners, and means to start saidburners.

2. The incinerator of claim 1 wherein said panels are twelve in numberand are bolted together.

3. The incinerator of claim 1 wherein the spark arrester is ofcylindrical construction and of locomotive netting material.

4. The incinerator of claim 1 wherein the grate means are railroadrails.

5. The incinerator of claim 1 wherein the pit means includes a hole inground.

6. The incinerator of claim 1 wherein the fuel supply means is a recyclesystem.

7. A method of disposing of combustible radioactive waste materialcomprising the steps of digging a hole in the ground at the site of theradioactive contamination; lining the hole with a steel basin to form alined pit; providing the lined pit with a grate means on the bottom ofsaid pit; providing forced externally supplied air beneath said grate;providing a number of panels; assembling the panels together in threeseparate conically shaped sections; nesting the three sections Withineach other to form a lower, center, and upper section structure; placingthe nested sections over said pit; providing the lower section with acharge door; providing the lower and center sections with burner anddamper means; providing the upper section with a spark arrester means;charging the pit with a supply of combustible radioactive Waste; burningsaid waste; collapsing said three sections into said pit when burning iscompleted; replacing the earth in the hole which Was utilized as thepit.

References Cited UNITED STATES PATENTS 1,776,914 9/ 1930 Langford.3,137,253 6/1964 Clayton -18 X 3,149,598 9/1964 Rees et al. 11018 XJAMES W. WESTHAVER, Primary Examiner.

-U.S. Cl. X.R.

